A few words may suffice as to what Nature has done towards the formation of nations and States by the configuration of the surface of the dry land--that is to say, by mountain chains and by river valleys. The only natural boundaries, besides seas, are mountains and deserts. Rivers, though convenient frontier lines for the politician or the geographer, are not natural boundaries, but rather unite than dissever those who dwell on their opposite banks. Thus the great natural boundaries in Asia have been the deserts of Eastern Persia, of Turkestan, and of Northern Arabia, with the long Himalayan chain and the savage ranges apparently parallel to the Irawadi River, which separate the easternmost corner of India and Burmah from South-Western China. To a less extent the Altai and Thian Shan, and, to a still smaller extent, the Taurus in Eastern Asia Minor, have tended to divide peoples and States. The Caucasus, which fills the space between two great seas, has been at all times an extremely important factor in history, severing the nomad races of Scythia from the more civilised and settled inhabitants of the valleys of the Phasis and the Kura. Even to-day, when the Tsar holds sway on both sides of this chain, it constitutes a weakness in the position of Russia, and it helps to keep the Georgian races to the south from losing their identity in the mass of Russian subjects. [Sidenote: The Place of Mountains in History] Without the Alps and the Pyrenees, the annals of Europe must have been entirely different. The Alps, even more than the Italian climate, proved too much for the Romano-Germanic Emperors of the Middle Ages, who tried to rule both to the north and to the south of this wide mountain region. The Pyrenees have not only kept in existence the Basque people, but have repeatedly frustrated the attempts of monarchs to dominate both France and Spain. The mass of high moorland country which covers most of the space between the Solway Firth and the lower course of the Tweed has had something to do with the formation of a Scottish nation out of singularly diverse elements. The rugged mountains of Northern and Western Scotland, and the similar though less extensive hill country of Wales, have enabled Celtic races to retain their language and character in both these regions. [Sidenote: What Steam-power has Done]